Removing snapped bolts

**Aaronhl** · 04-28-2023, 10:49 AM

So test to try to get one head bolt remnants out by welding, kept snapping the hex nut off, called a machine shop and he said he needs to look at the block in person - started disassembly last night and here is where im at

Half the bolts are american and the other metric, Merc had the collaboration with Yamaha on this one

**Aaronhl** · 04-28-2023, 10:50 AM

Merc did a collaboration with Yamaha on this one, half the bolts are American the other half Metric !!
Not like the 2.5s

**Aaronhl** · 04-28-2023, 11:01 AM

Anyone have ideas on non Merc head bolt options and if they will work well because the Merc bolts are garbage, especially the longer ones for the thermostat housing

**Glastron1987** · 04-29-2023, 06:41 AM

I have a bolt like that in my mid section. Haven't tried this yet, but this is what I am told will work... Clean it good, get a mig gas welder, aim it straight into the bolt and try not to hit the aluminum walls. The weld will stick to the steal, but not the aluminum. I think that is because the denser material draws in the heat. Glob it up good until you have something to grab onto to unscrew. Let me know how it worked they I'll try my mid section

**derekfl** · 04-29-2023, 06:43 AM

Why don’t you try it on your midsection and see how it works and then let him know how well it works.

**XstreamVking** · 04-29-2023, 07:05 AM

For fasteners down the hole use a pc of copper tube to protect the walls and the weld wont stick to them.

**OnPad** · 04-29-2023, 10:42 AM

Might be able to weld a pipe to deep broken bolts.
You could also build a drill jig to drill or machine bolts out.

Patience, heat, and penetration oil, is much better than having to deal with all this stuff.

Good luck!

**derekfl** · 04-30-2023, 06:08 AM

there is a guy in spring hill fl with a couple of these for 100 bucks each. still assembled blocks with cranks in and heads on. i bet you can drive to florida and buy 2 of them and drive back quicker and cheaper than tryne fix this motor. he is willing to pop all the head bolts to make sure not frozen. but he doesn't wanna ship. https://www.facebook.com/marketplace...ssenger_banner

**David - WI** · 04-30-2023, 10:25 AM

You can dissolve steel bolts out of aluminum with alum (for making pickles, I think). It takes awhile but costs almost nothing... you can probably do all the bolts on one head at the same time.

https://www.snaderflyby.com/dissolvi...alum-powder/#:

**Chaz** · 04-30-2023, 03:25 PM

This is why there is a shop rate .. and then another rate for .. if you have tried to work on it yourself already ...

Can still be fixed .. but will need welding the deck / hole area.

Two things come to mind :

1) ya gotta find center.

2) ya gotta mill the top flat.

OK 3) ya need the proper drill bit / end mill material.

Emm 4) spindle speed.

**David - WI** · 04-30-2023, 04:20 PM

I have made drill bushings in the lathe, out of short bolts... then screw them in a turn or two or whatever you can and drill though the center of the broken bolt with a small bit to get the "center".

**Aaronhl** · 05-02-2023, 10:47 PM

**************For the record I was not the person that tried to drill them out*************

Yes freshly snapped bolts are way easier to get out, too bad he didnt sell me the engine at that time...
I found scrapeing the dandriff outta the threads first and then pouring mystery oil helps before getting a good weld on the bolt,
A few of the remanants bolts were actually pretty easy to get out as I welded a steel rod on,
I only have 2 of the original 11 stuck bolts left to get out...

So how am I doing so far ???????????????

I took the other head off (that the previous guy did not touch), I actually snapped a few bolts, you can see in the first pic and then towards the last pics I am taking out the remnants of the drilled off center bolts...

**Aaronhl** · 05-02-2023, 10:53 PM

How easy is it to weld into this block? I need to figure out how to fill around the screws...there are a few short pockets the guy drilled that need to be filled and also one or two areas close to the o-ring...each of the bolts have partial threads, you can see one shot in the post above

**idvette** · 05-05-2023, 08:38 PM

Man that's ugly. What if you made a jig off the head bolt holes to keep your drill straight and in the right spot? Then drill oversized and helicoil?

**lbhsbz** · 05-07-2023, 10:12 PM

Find an old scrap cylinder head, overdrill some of the holes (where you need to) and install steel drill bushings. Bolt the head on and use a quality HSS drill through the bushings to re-drill your bad holes.